How Easily Can Bad Guys Become Good Guys?

This seems to me to be a little much:

The Cincinnati Bengals and former Pittsburgh Steelers linebacker James Harrison will try to complete a deal this week, a source familiar with situation told ESPN NFL Insider Adam Schefter.
Harrison and former Miami Dolphins linebacker Karlos Dansby each visited Cincinnati last week, and while the Bengals are interested in Dansby, a deal with Harrison seems more attainable and realistic at this time.
The Bengals have a need at outside linebacker, as 2012 starter Manny Lawson signed with the Buffalo Bills this offseason.
The 34-year-old Harrison, who was set to make $6.57 million in 2013, was released by the Steelers last month after refusing to take a pay cut. His agent said his client would be open to a return to the Steelers, but the Pittsburgh Post-Gazette reported that the team is not interested in a reunion.
Harrison was meeting with the Baltimore Ravens on the same day Baltimore reached agreement with linebacker Elvis Dumervil, which ended the team's interest in signing Harrison. Otherwise he has received little interest from teams looking for a linebacker.

James Harrison?  It's like the Rebel Alliance bringing Darth Vader on board.  Sure, he's a heck of a player, but it is always nice to have your enemies so perfectly represented.  Making the mind-bending switch from bad guy to good guy is hard for me to imagine.